Shock absorbers, gripping devices, robot arms, and jigs

Abstract

To enhance coaxiality between a central axis of a wrist of a robot arm and a central axis of a gripping member.SOLUTION: A buffering device comprises a support member that is mounted with a gripping member, and a base member that is mounted with a robot arm. The support member comprises an elastic part that is extended and contracted by impact applied to the gripping member, and a linearly-moving part that moves linearly together with the gripping member in response to displacement of the gripping member caused by the extension and contraction. The base member comprises a hole formed at a position which is coaxial with the central axis of the gripping member.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a buffer device, a gripping device, a robot arm, and a jig.

Background Art

[0002] A buffer device for a robot arm that absorbs the impact generated when a gripping member attached to the robot arm contacts a workpiece or the like is known. For example, a first member connected to either the hand portion or the arm portion, a second member disposed at an interval from the first member and connected to the other of the hand portion and the arm portion, and a connecting member that connects the first member and the second member in a state where the relative position of the two members with respect to the first member can be changed, and an elastic member that biases the first member so as to move away from the second member and is stretchable are provided. A connection member for a robot hand is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The working accuracy of a robot arm is affected by the coaxiality between the central axis of the wrist of the robot arm and the central axis of the gripping member. When a buffer device is attached to the robot arm, the coaxiality is lower than when the gripping member is directly attached to the robot arm. When the wrist of the robot arm rotates, the tip of the gripping member is likely to be eccentric. If the tip of the gripping member is eccentric, the working accuracy of the robot arm may decrease.

[0005] In one aspect, the objective is to provide a cushioning device, a gripping device, a robot arm, and a jig that can increase the coaxiality between the central axis of the robot arm's wrist and the central axis of the gripping member. [Means for solving the problem]

[0006] In one embodiment, the shock absorber comprises a support member to which a gripping member is attached, and a base member to which a robot arm is attached. The support member comprises an elastic portion that expands and contracts in response to an impact applied to the gripping member, and a linear portion that moves linearly together with the gripping member in accordance with the displacement of the gripping member due to the expansion and contraction. The base member comprises a hole provided at a position coaxial with the central axis of the gripping member. A connecting portion for connecting the base member and other members can be fitted into the hole from one side in the axial direction, and a pin or jig used for aligning the base member and the gripping member can be attached to and detached from the other side in the axial direction of the hole.

[0007] According to one embodiment, the degree of coaxiality between the central axis of the robot arm's wrist and the central axis of the gripping member can be increased. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing an example of a gripping device in the first embodiment. [Figure 2] Figure 2 is a perspective view showing an example of a buffer device in the first embodiment. [Figure 3] Figure 3 is a side view showing an example of a robot arm in the first embodiment. [Figure 4] Figure 4 is a bottom perspective view showing an example of a gripping device in the first embodiment. [Figure 5] Figure 5 is an exploded side view showing an example of a gripping device attached to a robot arm in the first embodiment. [Figure 6] Figure 6 is a bottom perspective view showing an example of the gripping device in the first embodiment with the base plate member removed. [Figure 7] Figure 7 is a side view showing an example of the state of the gripping device during assembly in the first embodiment. [Figure 8]Figure 8 is an enlarged perspective view showing an example of the gripping device in the first embodiment during assembly. [Figure 9] Figure 9 is a side view showing an example of a gripping device after assembly in the first embodiment. [Figure 10] Figure 10 is a side cross-sectional view showing an example of a gripping device in the first embodiment. [Figure 11] Figure 11 is a perspective view showing an example of a gripping device in which the position of the support member has been changed in the first embodiment. [Figure 12] Figure 12 is a perspective view showing an example of the connection state between the base plate and the support member in the first embodiment. [Figure 13] Figure 13 is a perspective view showing an example of a gripping device and a jig attached to the gripping device in the second embodiment. [Figure 14] Figure 14 is a perspective view showing an example of a gripping device with the base plate removed in the second embodiment. [Figure 15] Figure 15 is a perspective view showing an example of the gripping device in the second embodiment during assembly. [Figure 16] Figure 16 is an enlarged perspective view showing an example of the gripping device in the second embodiment during assembly. [Modes for carrying out the invention]

[0009] The embodiments of the cushioning device, gripping device, robot arm, and jig disclosed in this application will be described in detail below with reference to the drawings. However, this invention is not limited by these embodiments. Furthermore, the dimensional relationships and ratios of the elements in the drawings may differ from reality. There may also be differences in dimensional relationships and ratios between drawings. In some drawings, for the sake of clarity, a coordinate system may be shown in which the direction in which the claws 41a and 41b extend is the Y-axis direction, and the direction in which the claws 41a and 41b move is the Z-axis direction. Also, the contents described in one embodiment or modification generally apply similarly to other embodiments and modifications.

[0010] (First Embodiment) First, the buffer device 2 in the first embodiment will be described with reference to FIG. 1. FIG. 1 is a perspective view showing an example of a gripping device in the first embodiment. FIG. 2 is a perspective view showing an example of the buffer device in the first embodiment. FIG. 3 is a side view showing an example of the robot arm in the first embodiment. FIG. 4 is a bottom perspective view showing an example of the gripping device in the first embodiment. FIG. 5 is an exploded side view showing an example of the gripping device attached to the robot arm in the first embodiment. FIG. 6 is a bottom perspective view showing an example of the state where the base plate member of the gripping device in the first embodiment is removed. As shown in FIG. 1, the gripping device 1 in the present embodiment includes a gripping member 4 and a buffer device 2 shown in FIG. 2. The gripping device 1 is attached to a robot arm 6 etc. shown in FIG. 3 via a base plate 20 of the buffer device 2. The robot arm 6 shown in FIG. 3 is in the first embodiment gripping member 4 shows a case where a different gripping member 40 is connected to the wrist 61. The gripping member 40 and the wrist 61 are attached so that, for example, the central axis AX9 is coaxial. Note that the robot arm 6 is not limited to the vertically articulated robot arm shown in FIG. 3. For example, the robot arm 6 may be any industrial robot such as a scalar type (horizontally articulated type), a Cartesian coordinate type, or a parallel link type.

[0011] As shown in FIG. 2, the buffer device 2 includes a base plate 20 and a support member 30. The support member 30 includes a fixing portion 31, a linear guide 32, coil springs 33a and 33b, a back plate 35, and adjustment screws 36a and 36b.

[0012] The base plate 20 is connected to the robot arm 6 shown in FIG. 3. Note that the base plate 20 is an example of a base member. Through holes 29 shown in FIG. 2, long holes 27a and 27b shown in FIG. 4, and a hole 28 are formed in the base plate 20.

[0013] Incidentally, the base plate 20 may further include a hole 24 through which a stroke end 23 that limits the movable range of the fixing portion 31 is inserted, and a robot arm mounting portion 26. The robot arm mounting portion 26 is, for example, a plurality of holes or recesses extending in the Y-axis direction. A bolt or the like for fixing the robot arm 6 and the base plate 20 is inserted into the robot arm mounting portion 26. In the first embodiment, a plurality of types of robot arm mounting portions 26 having different positions and sizes are formed on the base plate 20 according to the difference in the shape of the robot arm 6.

[0014] The long holes 27a and 27b are through holes having a substantially oval shape that extends in the Y-axis direction and has a long cross section in the X-axis direction. Bolts 7a and 7b for fixing the base plate 20 and the back plate 35 are respectively inserted into the long holes 27a and 27b. The hole 28 is a through hole having a substantially circular cross section that extends in the Y-axis direction. A portion of the fixing pin 8 shown in FIG. 6 that protrudes in the negative Y-axis direction is inserted into the hole 28. The fixing pin 8 is inserted into the pin insertion portion 38 of the back plate 35, thereby suppressing the back plate 35 from rattling with respect to the base plate 20.

[0015] The through hole 29 is a hole that penetrates the base plate 20 in the Y-axis direction. The through hole 29 is fixed at a position that is coaxial with the central axis AX4 of the gripping member 4 shown in FIG. 5, for example. An engaging protrusion 69a of the connection portion 69 of the robot arm 6 shown in FIG. 5 and the alignment pin 9 shown in FIG. 5 are fitted into the through hole 29.

[0016] The back plate 35 of the support member 30 is fixed to the base plate 20. The back plate 35 includes a rail 32b. A moving block 32a attached to the fixing portion 31 is fixed to the rail 32b so as to be movable in the Y-axis direction. The rail 32b and the moving block 32a constitute a linear guide 32 which is an example of a linear motion portion.

[0017] Furthermore, as shown in Figure 6, the back plate 35 is provided with screw holes 37a and 37b and a pin insertion portion 38 on the side facing the negative Y-axis. The screw holes 37a and 37b are recesses with a roughly circular cross-section that extend, for example, in the Y-axis direction. Bolts 7a and 7b, which fix the base plate 20 and the back plate 35, are screwed into the screw holes 37a and 37b.

[0018] The pin insertion portion 38 is, for example, a recess formed in the positive Y-axis direction, and its cross-section is formed in a substantially oval shape that is elongated in the X-axis direction. A fixing pin 8 is inserted through the pin insertion portion 38.

[0019] A gripping member 4 is fixed to the positive X-axis side of the fixing part 31. The fixing part 31 is connected to the back plate 35 so as to be movable along the linear guide 32 in the direction indicated by the arrow in Figure 2 (Y-axis direction).

[0020] The fixing portion 31 comprises coil springs 33a and 33b and adjustment screws 36a and 36b. A projection 34a is formed on the surface of the fixing portion 31 facing the positive X-axis direction. Multiple bolts 34b may also be inserted through the fixing portion 31 from the negative X-axis direction to the positive X-axis direction. The fixing portion 31 can be removed from the back plate 35 by, for example, removing the adjustment screws 36a and 36b and pulling it out from the rail 32b in the Y-axis direction.

[0021] As shown in Figure 5, the coil springs 33a and 33b, the linear guide 32, and the gripping member 4 are arranged in the direction of the X-axis, that is, in a direction intersecting the direction in which the through hole 29 extends (Y-axis).

[0022] The coil springs 33a and 33b absorb the impact applied from the gripping member 4. The pair of coil springs 33a and 33b are arranged facing each other in the Z-axis direction. Note that the coil springs 33a and 33b are examples of elastic parts.

[0023] The adjustment screws 36a and 36b attach the coil springs 33a and 33b to the fixing part 31, respectively, and adjust the biasing force of the coil springs 33a and 33b, or adjust the position of the fixing part 31 in the Y-axis direction.

[0024] As shown in Figure 1, the gripping member 4 comprises claws 41a and 41b, movable blocks 42a and 42b, a rail 43, a main body 44, a drive unit 45, and a frame 50.

[0025] The pair of claws 41a and 41b are the parts that grip the workpiece (object to be gripped), and as shown in Figure 1, they are arranged opposite each other in the Z-axis direction. The claws 41a and 41b are fixed to the moving blocks 42a and 42b respectively by bolts or the like, and move in conjunction with the moving blocks 42a and 42b in the direction indicated by the arrow (Z-axis direction).

[0026] A pair of movable blocks 42a and 42b are arranged to be movable along a rail 43 in the Z-axis direction. The rail 43 is positioned opposite to the movable blocks 42a and 42b in the X-axis direction. The rail 43 is fixed to the main body 44, for example, by bolts.

[0027] The drive unit 45 is equipped with, for example, a motor and is driven by power supplied from an external source. The main body 44 is equipped with transmission mechanisms such as a rack and pinion mechanism, a cam mechanism, a lead screw mechanism, and a belt mechanism, and moves the movable blocks 42a and 42b by the driving force of the drive unit 45.

[0028] The frame 50 holds the main body 44 and the drive unit 45. The frame 50 has an upper surface 51 located on the positive Y-axis side, a side surface 52 located on the negative X-axis side, and a bottom surface 53 located on the negative Y-axis side. The main body 44 is fixed to the upper surface 51, for example, by bolts. The upper surface 51 may also have a hole (not shown) through which the drive unit 45 is inserted in the Y-axis direction.

[0029] The side surface 52 is provided with holes 54a at positions corresponding to the projections 34a formed on the fixing portion 31 of the support member 30. The side surface 52 is also provided with a plurality of screw holes 54b at positions corresponding to the plurality of bolts 34b inserted into the fixing portion 31. The side surface 52 is fixed to the shock absorber 2. Specifically, as shown in Figure 5, the holes 54a formed in the side surface 52 engage with the projections 34a of the shock absorber 2 shown in Figure 2. The plurality of bolts 34b are screwed into the plurality of screw holes 54b. The gripping member 4 is attached to the fixing portion 31 of the shock absorber 2, for example, when the fixing portion 31 of the shock absorber 2 is removed from the back plate 35.

[0030] As shown in Figures 5 and 6, a through hole 59 is formed in the bottom surface 53 at the position of the central axis of the gripping member 4. Other through holes 55 may also be formed in the bottom surface 53, for example, through which bolts connecting to the base plate 20 or the robot arm 6 are inserted.

[0031] The robot arm 6 comprises multiple joints, including a wrist 61. In the first embodiment, the robot arm 6 has six joints 61 to 66, as shown in Figure 3. The six joints 61 to 66 are connected to a base portion 67.

[0032] The robot arm 6 is connected to the shock absorber 2, for example, by the wrist 61 being connected to the base plate 20 via a connecting portion 69. Specifically, with the fitting portion 69c of the connecting portion 69 shown in Figure 5 fitted onto the wrist 61, the engaging projection 69a of the connecting portion 69 is inserted through the through hole 29 of the base plate 20. In this case, the contact portion 69b of the connecting portion 69 contacts the base plate 20 in the Y-axis direction. At that time, the connecting portion 69 is fitted onto the wrist 61 such that the engaging projection 69a is located coaxially with the central axis AX1 of the wrist 61. The contact portion 69b may also have a through hole or recess formed therein, which is connected to the robot arm mounting portion 26 of the base plate 20 by a bolt.

[0033] Then, as shown in Figure 5, the gripping member 4 is connected to the shock absorber 2, which is connected to the robot arm 6, via the frame 50. At this time, the shock absorber 2 is connected to the gripping member 4 such that the central axis AX4 of the gripping member 4 is located coaxially with the central axis AX1 of the wrist 61 of the robot arm 6.

[0034] The gripping member 4 may be displaced by impacts such as when the claws 41a or 41b come into contact with the object to be gripped or a tray while moving, or when stacked objects to be gripped fall and collide with the claws 41a or 41b. In this case, because the gripping member 4 is connected to the robot arm 6 via the shock absorber 2, the linear guide 32 of the shock absorber 2 restricts the direction of displacement to the Y-axis direction, suppressing the gripping member 4 from wobbling in other directions. Furthermore, the shock is absorbed by the coil springs 33a and 33b, suppressing displacement in the Y-axis direction as well. As a result, even when the gripping member 4 is subjected to an impact, the displacement of the gripping member 4 is suppressed.

[0035] On the other hand, the central axis of the shock absorber 2 in the Y-axis direction is not coaxial with either the central axis AX1 of the wrist 61 of the robot arm 6 shown in Figure 3, or the central axis AX4 of the gripping member 4 shown in Figure 5. In this case, compared to the case where the robot arm 6 and the gripping member 4 are directly connected, the coaxiality between the central axis of the robot arm 6 and the central axis of the gripping member 4 decreases due to the accumulation of errors caused by the presence of multiple intervening members.

[0036] Therefore, in the first embodiment, a method for adjusting the coaxiality between the gripping member 4 and the wrist 61 of the robot arm 6 by using the alignment pin 9 and the through hole 29 of the base plate 20 will be explained with reference to Figures 5 to 10. Figure 7 is a side view showing an example of the state of the gripping device during assembly in the first embodiment. Figure 8 is an enlarged perspective view showing an example of the state of the gripping device during assembly in the first embodiment. Figure 9 is a side view showing an example of the gripping device after assembly in the first embodiment. Figure 10 is a side cross-sectional view showing an example of the gripping device in the first embodiment. Figure 8 is an enlarged perspective view of the portion shown in frame F1 of Figure 7. Figure 10 shows a cross-section of the state in which the alignment pin 9 and the robot arm 6 are connected to the buffer device 2 shown in Figure 1, cut along line AA in Figure 1.

[0037] As shown in Figures 5 and 10, the robot arm 6 is attached to the shock absorber 2 such that the central axis AX1 of the wrist 61 is inserted through the through hole 29 of the base plate 20. At that time, the alignment pin 9 shown in Figure 5 is further inserted through the through hole 29 of the base plate 20. Note that, as shown in Figure 10, the engaging projection 69a of the connection portion 69 of the robot arm 6 may be made of a separate component from the contact portion 69b.

[0038] As shown in Figure 10, the alignment pin 9 comprises a flange portion 91 and protrusions 94 and 96. The protrusion 94 is formed on the positive Y-axis side relative to the flange portion 91, and the protrusion 96 is formed on the negative Y-axis side relative to the flange portion 91.

[0039] When the gripping member 4 is attached to the cushioning device 2, the positional relationship between the gripping member 4 and the base plate 20 is adjusted so that the protrusion 94 of the alignment pin 9 is inserted through the through hole 59 formed in the bottom surface 53 of the frame 50, as shown in Figures 7 and 8.

[0040] As shown in Figure 7, when the gripping member 4 is pushed down in the negative direction of the Y-axis, the position of the gripping member 4 in the X-axis direction is adjusted so that the alignment pin 9 is inserted through the through hole 59 in the bottom surface 53 of the gripping member 4. This makes it easy to mount the gripping device 1, which includes the shock absorber 2 and the gripping member 4, so that the central axis of the motor of the gripping member 4 is coaxial with the through hole 59 in the frame 50.

[0041] Furthermore, after the gripping device 1 is assembled, the alignment pin 9 will obstruct the movement of the gripping member 4, so it is desirable to remove it after the position has been aligned. For example, when the coil springs 33a and 33b, which were compressed when the gripping member 4 was pushed down in the negative Y-axis direction, are released, the linear guide 32 of the support member 30 causes the gripping member 4 to move in the positive Y-axis direction without changing its position in the X-axis and Z-axis directions. As a result, as shown in Figure 10, the alignment pin 9 detaches from the through hole 59 of the frame 50, so that the alignment pin 9 can be removed while maintaining the coaxial relationship between the gripping member 4 and the wrist 61 of the robot arm 6.

[0042] Furthermore, as a result of aligning the gripping member 4 in the X-axis direction, the support member 30 to which the gripping member 4 is connected may be offset in the X-axis direction by a width W1 relative to the base plate 20, as shown in Figure 11. Figure 11 is a perspective view showing an example of a gripping device in which the position of the support member in the first embodiment has been changed.

[0043] In this case, when bolts 7a and 7b are inserted through the base plate 20 and back plate 35, the screw holes 37a and 37b in the back plate 35 are formed in a substantially circular cross-section, as shown in Figure 6. In contrast, the elongated holes 27a and 27b in the base plate 20 are formed in a substantially oval shape with a cross-section that is elongated in the X-axis direction, as shown in Figure 12. Figure 12 is a perspective view showing an example of the connection state between the base plate and the support member in the first embodiment. Note that in Figure 12, the base plate 20 is shown with a dashed line, and some structures such as the robot arm mounting portion 26 are not shown.

[0044] With this configuration, by fixing the bolts 7a and 7b at positions offset in the X-axis direction from the centers of the elongated holes 27a and 27b, the support member 30 can be fixed at a position offset in the X-axis direction from the base plate 20, as shown in Figure 11. The fixing pin 8 is inserted, for example, into the approximate center of the back plate 35 in the Z-axis direction. In this case, by rotating the back plate 35 with the fixing pin 8 as the axis of rotation in the Y-axis direction, the angle of the back plate 35 with respect to the Y-axis direction can be finely adjusted.

[0045] On the other hand, the pin insertion portion 38 formed in the back plate 35, through which the fixing pin 8 is inserted, has a substantially oval cross-section that is long in the X-axis direction, similar to the elongated holes 27a and 27b of the base plate 20. With this configuration, as shown in Figure 11, even when the back plate 35 is fixed with an offset of a width W1 in the X-axis direction relative to the base plate 20, a portion of the fixing pin 8 inserted through the pin insertion portion 38 of the back plate 35 can be inserted through the hole 28 of the base plate 20. In the first embodiment, the bolts 7a and 7b and the fixing pin 8, the elongated holes 27a and 27b and the hole 28 of the base plate 20, and the screw holes 37a and 37b and the pin insertion portion 38 of the back plate 35 constitute a sliding mechanism.

[0046] With this configuration, even when the support member 30 slides relative to the base plate 20 in the positive X-axis direction, as shown in Figure 12, play between the support member 30 and the base plate 20 can be suppressed.

[0047] As described above, the shock absorber 2 in the first embodiment comprises a support member 30 to which the gripping member 4 is attached, and a base member 20 to which the robot arm 6 is attached. The support member 30 comprises elastic parts 33a and 33b that expand and contract in response to an impact applied to the gripping member 4, and a linear motion part 32 that moves linearly together with the gripping member 4 in accordance with the displacement of the gripping member 4 due to the expansion and contraction. The base member 20 is provided with a hole 29 located at a position coaxial with the central axis of the gripping member 4. With this configuration, the degree of coaxiality between the central axis of the robot arm's wrist and the central axis of the gripping member can be increased.

[0048] Furthermore, in the first embodiment, the cushioning device 2 may also include a sliding mechanism that allows the support member 30 to be moved in parallel to adjust the coaxiality between the through hole 29 and the central axis AX4 of the gripping member 4. This makes it possible to suppress play between the gripping member 4 and the robot arm 6 when the gripping member 4 is fixed so that the central axis AX4 is coaxial with the central axis AX1 of the wrist 61 of the robot arm 6.

[0049] (Second embodiment) Although the first embodiment has been described above, the embodiment is not limited thereto. For example, as shown in Figures 13 to 16, a through hole may not be formed at the position of the central axis of the gripping member 4 on the bottom surface A53 of the frame A50. Figure 13 is a perspective view showing an example of a gripping device and a jig attached to the gripping device in the second embodiment. Figure 14 is a perspective view showing an example of a gripping device with the base plate removed in the second embodiment. Figure 15 is a perspective view showing an example of the gripping device in the second embodiment during assembly. Figure 16 is an enlarged perspective view showing an example of the gripping device in the second embodiment during assembly. Figure 16 is an enlarged view of the part shown in frame F2 of Figure 15. In the following embodiments and modifications, the same reference numerals are used for parts that are the same as those shown in the drawings described above, and redundant explanations are omitted.

[0050] In the gripping device A1 of the second embodiment, through holes A55a and A55b are formed in the bottom surface A53 of the frame A50 of the gripping member A4, as shown in Figure 14, at positions offset from the central axis of the gripping member A4. The through holes A55a and A55b are formed side by side, for example, in the X-axis direction. In addition, several other through holes A55c are also formed in the bottom surface A53. Through holes A55a, A55b and A55c to For example, bolts or the like are inserted when attaching the gripping member A4 to the robot arm 6 without using the shock absorber 2. In the second embodiment, the through hole A55a has a substantially oval cross-sectional shape that is long in the Z-axis direction, and the through hole A55b has a substantially circular cross-sectional shape.

[0051] In the second embodiment, the jig A9 shown in Figure 13 is used to align the gripping member A4 with the base plate 20. The jig A9 comprises a flange portion A91, protrusions A94a and A94b, and a protrusion A96. Protrusion A96 is an example of the first protrusion, and protrusions A94a and A94b are examples of the second protrusion.

[0052] The flange portion A91 is formed in a roughly rectangular shape that is elongated in the Z-axis direction. The protrusions A94a and A94b are formed on the positive Y-axis side relative to the flange portion A91, and the protrusion A96 is formed on the negative Y-axis side relative to the flange portion A91.

[0053] The protrusion A96 is formed approximately in the center in the Z-axis direction. The protrusion A96 is formed at a position corresponding to the through hole 59 in the base plate 20 of the buffer device 2.

[0054] The protrusions A94a and A94b are formed at positions offset from the center in the Z-axis direction. The protrusions A94a and A94b are formed at positions corresponding to the through holes A55a and A55b in the frame A50 of the gripping member A4. In this case, the protrusions A94a and A94b are not aligned in a straight line with the protrusion A96 in the Y-axis direction.

[0055] In the second embodiment as well, the engaging projection 69a of the connecting portion 69 of the robot arm 6 shown in Figure 5 is inserted through the through hole 29 of the base plate 20 of the shock absorber 2 from the negative Y-axis side. In the second embodiment, the jig A9 is inserted through the through hole 29 from the positive Y-axis side.

[0056] In this case, the protrusions A94a and A94b of the jig A9 are inserted through the through holes A55a and A55b of the frame A50 of the gripping member A4, thereby connecting the gripping member A4, the cushioning device 2, and the robot arm 6 so that the central axis AX5 of the gripping member A4 is coaxial with the central axis AX1 of the wrist 61 of the robot arm 6.

[0057] As described above, the jig A9 in the second embodiment includes a first protrusion 96 formed at a position corresponding to the hole 29 of the cushioning device 2, and second protrusions A94a and A94b formed at positions corresponding to the recesses or through holes A55a and A55b formed in the gripping member A4. With this configuration, the degree of coaxiality can be improved even if the gripping member does not have a hole or recess that is coaxial with the central axis of the wrist 61 of the robot arm 6.

[0058] Although various embodiments of the present invention have been described above, the embodiments are not limited thereto. For example, the gripping members 4 and A4 may have three or more claws, or they may be any end effector such as a suction type.

[0059] Furthermore, the hole 29 is not limited to a through hole; for example, it may be two recesses formed coaxially on the positive Y-axis side and the negative Y-axis side. Alternatively, the diameter of the hole 29 may differ on the positive Y-axis side and the negative Y-axis side, resulting in a so-called stepped hole. The same applies to other holes in the frame 50, such as hole 59 and hole 54b.

[0060] Furthermore, although a configuration using a fixing pin 8 to prevent rattling of the support member 30 has been described, the configuration is not limited to this, and for example, another member may be used to support the base plate 20 and the support member 30 from the negative X-axis direction.

[0061] Furthermore, the shape of the hole 28 and the pin insertion portion 38 is such that one of the cross-sections is approximately oval and the other is approximately circular. For example, the hole 28 may be an elongated hole and the cross-section of the pin insertion portion 38 may be approximately circular. Note that the hole 28 shown in Figure 10 is a stepped through hole, but is not limited to this; it may be a through hole without a step, or a non-through recess cut out from the positive Y-axis side to the negative Y-axis side.

[0062] Although the present invention has been described above based on various embodiments and modifications, it goes without saying that the present invention is not limited to these embodiments and modifications, and that various modifications are possible without departing from the spirit of the invention. Such modifications without departing from the spirit are also included within the technical scope of the present invention, and this will be clear to those skilled in the art from the description of the claims. [Explanation of Symbols]

[0063] 1,A1 Gripping device, 2 Shock absorber, 4,A4 Gripping member, 6 Robot arm, 7a,7b Bolt, 8 Fixing pin, 9 Alignment pin, 20 Base plate, 27a,27b Slotted hole, 28 Hole, 29 Through hole, 30 Support member, 31 Fixing part, 32 Linear guide, 32a Moving block, 32b Rail, 33a,33b Coil spring, 35 Back plate, 36a,36b Adjustment screw, 37a,37b Screw hole, 38 Pin insertion part, 40 Gripping member, 41a,41b Claw, 42a,42b Moving block, 43 Rail, 44 Main body, 45 Drive unit, 50,A50 Frame, 51 Top surface, 52 Side surface, 53,A53 Bottom surface, A55a~A55c Through hole, 59 Through hole, 61; Wrist, 61-66; Joint, A9; Jig, 91, A91; Flange, 94, A94a, A94b, 96, A96; Protrusion

Claims

1. A support member to which a gripping member is attached, A base member to which the robot arm is attached, Equipped with, The aforementioned support member is An elastic portion that expands and contracts in response to an impact applied to the gripping member, A linear motion part that moves linearly together with the gripping member in accordance with the displacement of the gripping member due to the aforementioned expansion and contraction, Equipped with, The base member is The gripping member is provided with a hole located at a position coaxial with the central axis of the gripping member, A connecting portion for connecting the base member and another member can be fitted into the hole from one side in the axial direction, and a pin or jig used for aligning the base member and the gripping member can be attached to and detached from the other side in the axial direction of the hole. Buffer device.

2. A support member to which a gripping member is attached, A base member to which the robot arm is attached, A sliding mechanism, Equipped with, The aforementioned support member is An elastic portion that expands and contracts in response to an impact applied to the gripping member, A linear motion part that moves linearly together with the gripping member in accordance with the displacement of the gripping member due to the aforementioned expansion and contraction, Equipped with, The base member is The gripping member is provided with a hole located at a position coaxial with the central axis of the gripping member, The sliding mechanism can adjust the coaxiality between the hole and the central axis by moving the support member in parallel. Buffer device.

3. The cushioning device according to claim 1, wherein the elastic portion, the linear portion, and the gripping member are arranged in a direction intersecting the direction in which the hole extends.

4. The aforementioned hole is a through hole, The shock absorber according to claim 1, wherein the base member is attached to the tip of the robot arm, and is provided coaxially with the rotation axis of the tip of the robot arm.

5. A buffer device according to any one of claims 1 to 4, A gripping device in which the central axis of the motor of the gripping member is adjusted to be coaxial with the hole.

6. The gripping device is provided as described in claim 5, A robot arm in which the central axis of the motor of the gripping member is adjusted to be coaxial with the rotation axis of the tip of the robot arm.

7. A jig comprising a first protrusion formed at a position corresponding to the hole in the cushioning device according to any one of claims 1 to 4, and a second protrusion formed at a position corresponding to a recess or hole formed in the gripping member.

8. The jig according to claim 7, wherein the first protrusion and the second protrusion are not located in a straight line in the axial direction.

Images